Sichuan province , China -LRB- CNN -RRB- -- It 's after 10 p.m. when we see a light in the distance . We 've traveled for more than three hours up a windy , icy road in western China .

Our hope is to get to the Tibetan autonomous zone , in the mountainous region of Sichuan province , an area reportedly locked in an ever-growing spiral of violence .

We 're so close , only an hour or so away . And then the light .

Within minutes , we grind to a halt . A policeman is flashing a flashlight in my face . Our Chinese driver is already outside the car . We wo n't be going any farther tonight .

Roadblocks like this are strewn across the back roads of this province . For weeks , ethnic Tibetans and Chinese security forces have been locked in conflict .

Buddhist nuns and monks have been carrying out ritual self-immolation . It is a gruesome protest against what they claim is the ongoing oppression by Chinese authorities .

Timeline of Tibetan protests in China

As our car turns back , our driver calls a Tibetan contact . Something serious is going down . The Tibetan says his village is crawling with police and the military . Later , local news reports tell of two Tibetans killed in protests .

But many of the villages that straddle the mountains are inhabited by Han Chinese , the dominant ethnic group in China . Inside the houses , lights are on , as people eat , watch TV and talk . We ask what they 're hearing . They tell us they have little time for the Tibetans . They call them lazy and accuse them of living off government handouts .

One woman claims the Han Chinese are being targeted by violent Tibetan gangs . Local media reports say more than a dozen people have already been killed .

There is hysteria , bigotry and fear here . It is fueled by government secrecy and a constant stream of military and police vehicles . Much of the province is in lockdown .

In the capital city of Chengdu , police vehicles are seen moving into position at dawn . Soon , they are on every corner , armed police patrolling the streets . They are tightening their grip on this heavily Tibetan populated neighborhood .

It 's hard to get people to talk here . We see a group of young monks on a corner and wave them over . They agree to take us to their living quarters . Here in a tiny one bedroom apartment , four beds crammed against the walls and their food tied in sacks , the monks tell us they are verbally abused and harassed by police , pushed to breaking point .

`` I can not bear it any longer - any more , '' says one .

They are far from their home in the mountains ; cut off they say , they can not even make contact by phone .

`` We want to go but we can not , you can see all the security out there . Wherever you go , they see you . We can not go anywhere , '' he says .

We ask if he 's afraid , but he just looks at a picture of the Buddha , a smile on his face .

`` I ca n't explain , '' he says , `` but I 'm not afraid . ''

In their pouch , the monks hold a keepsake of their spiritual leader the Dalai Lama , too sacred to even show us . This pouch , they say , carries a dream .

`` We wish what all Tibetans wish for the most : for the Dalai Lama to return to the palace in Tibet . ''

They know about the self-immolation of other Buddhists ; they say they support them and vow it will continue until China leaves Tibet .

For the Chinese government , though , these are dangerous men -- part of what they call a `` splittist '' element , determined to tear Tibet from China .

Throughout our interview , we have been watched . Later , our vehicle is followed . Our driver says his family has received threatening phone calls .

On our way to the airport , a car , rather suspiciously , rams into the back of our taxi .

As we make our way to the service counters , we are followed by plainclothes security talking constantly on mobile phones . Eventually trying to clear airport security , we 're grabbed by police . We are marched to an airport police station and detained and questioned for five hours . Police keep some of our video .

They want to know who we spoke to , what we are doing here , where we 've been and why we want to cover this story . We have our own questions -- questions authorities are answering only with roadblocks and police .

Later , Chinese authorities black out CNNI when our report airs about the situation in the ethnically Tibetan area .

There are claims and counter-claims in this dark conflict . All of it is being played out behind a veil of secrecy in the mountains of western China .

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NEW : Chinese authorities black out a CNN report on the situation in Tibet

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Buddhist nuns and monks have been carrying out ritual self-immolation

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They are protesting against what they claim is the ongoing oppression by Chinese authorities

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Beijing says these are dangerous men determined to tear Tibet from China